WARMING 1.5C ABOVE PRE-INDUSTRIAL

Posted by: chaamjamal on: July 11, 2020

• In: Uncategorized
 
• 4 Comments

 

THE UNITED NATIONS IPCC:  CATASTROPHIC IRREVERSIBLE CLIMATE CHANGE IF WARMING SINCE PRE-INDUSTRIAL EXCEEDS THE CRITICAL VALUE THAT THE IPCC HAS USED CLIMATE MODELS TO DETERMINE.  

QUESTION: WHAT DOES PRE-INDUSTRIAL MEAN? IN WHAT YEAR DID AGW HUMAN CAUSED CLIMATE CHANGE START?

ANSWER:

1. Callendar 1938 . It started in 1900 and warmed steadily from 1900 to 1938 with the warming driven by rising CO2 which in turn is attributable to fossil fuel emissions.
2. Hansen 1988 .  It started in 1950 because in the 30-year period 1950-1980 there is a strong measurable warming rate with 99% probability for human cause.
3. UNITED NATIONS IPCC 2001: It started in 1750 when the Industrial Revolution kicked in and atmospheric CO2 began to rise.
4. UNITED NATIONS IPCC 2015: It started in 1850 by when sufficient fossil fuel carbon had entered the atmosphere for a measurable response of temperature to CO2.
5. NASA 2020 : It started in 1950 because from then the relationship between CO2 and temperature we see in the climate models closely matches the observational data.
6. Climate Scientist Peter Cox 2018 : It started in the 1970s because it is since then that we see a measurable responsiveness of surface temperature to atmospheric CO2 concentration according to the theory of the greenhouse effect of CO2.

 

QUESTION: HOW MUCH WARMING SINCE PRE-INDUSTRIAL WILL CAUSE A CLIMATE CHANGE TIPPING POINT AND IRREVERSIBLE CATASTROPHIC CLIMATE CHANGE? 

ANSWER:

1. UNITED NATIONS IPCC 2001:  Warming must not be allowed to exceed 5C. If we don’t take climate action to reduce and eliminate emissions, the temperature will continue to go up and when it warms 5C above pre-industrial, warming will become irreversible and it will no longer be possible to attenuate warming with climate action.
2. UNITED NATIONS IPCC 2007:  Warming must not be allowed to exceed 4C. If we don’t take climate action to reduce and eliminate emissions, the temperature will continue to go up and when it warms 4C above pre-industrial, warming will become irreversible and it will no longer be possible to attenuate warming with climate action.
3. UNITED NATIONS IPCC 2013:  Warming must not be allowed to exceed 3C. If we don’t take climate action to reduce and eliminate emissions, the temperature will continue to go up and when it warms 3C above pre-industrial, warming will become irreversible and it will no longer be possible to attenuate warming with climate action.
4. UNITED NATIONS IPCC 2015:  Warming must not be allowed to exceed 2C. If we don’t take climate action to reduce and eliminate emissions, the temperature will continue to go up and when it warms 2C above pre-industrial, warming will become irreversible and it will no longer be possible to attenuate warming with climate action.
5. UNITED NATIONS IPCC 2018:  Warming must not be allowed to exceed 1.5C. If we don’t take climate action to reduce and eliminate emissions, the temperature will continue to go up and when it warms 1.5C above pre-industrial, warming will become irreversible and it will no longer be possible to attenuate warming with climate action.

 

QUESTION: WHAT ABOUT THE INTERNAL VARIABILITY OF THE CLIMATE SYSTEM THAT IS BEYOND THE ABILITY OF HUMANS TO CONTROL?

ANSWER:   Insights from Earth system model initial-condition large ensembles and future prospects, C. Deser, F. Lehner, K. B. Rodgers, T. Ault, T. L. Delworth, P. N. DiNezio, A. Fiore, C. Frankignoul, J. C. Fyfe, D. E. Horton, J. E. Kay, R. Knutti, N. S. Lovenduski, J. Marotzke, K. A. McKinnon, S. Minobe, J. Randerson, J. A. Screen, I. R. Simpson & M. Ting: Nature Climate Change (2020). Abstract: Internal variability in the climate system confounds assessment of human-induced climate change and imposes irreducible limits on the accuracy of climate change projections, especially at regional and decadal scales. A new collection of initial-condition large ensembles (LEs) generated with seven Earth system models under historical and future radiative forcing scenarios provides new insights into uncertainties due to internal variability versus model differences. These data enhance the assessment of climate change risks, including extreme events, and offer a powerful testbed for new methodologies aimed at separating forced signals from internal variability in the observational record. Opportunities and challenges confronting the design and dissemination of future LEs, including increased spatial resolution and model complexity alongside emerging Earth system applications, are discussed.

TRANSLATION: There is an internal variability of the climate system for regional and short term effects that are beyond the ability of climate models  to explain. No assessment of regional climate or short term forecasts can be made of future climate states based only on fossil fuel emissions. Therefore,  regional or short term  climate change forecasts of climate  models contain uncertainties that are too large to make those forecasts.